Freeing up the Time Stuck 1959 Pontiac 389 Bonneville Engine

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maniacmechanic
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Well I got Lied to by the Old Guy that sold me my 1959 Pontiac Bonneville 389 4bbl engine.
Was advertised as turned freely.
Should have stated that was back in 1983 when Ronald Regan Was President of the USA.
I should have checked but Trusted the guy because I bought from him prior and he is about 80 years old.

Its a Very Common problem when you finally spot and look at the Untouched Musclecar engine. 90-99 % are rusted shut stuck if not Blown up and apart.
Mine is Stuck from Decades of sitting unused.

One day it will be an issue with all LS, LS-X, & New Gen C7 LT Corvette engines.
So I Figure I would document some how I am getting my 1959 Bonneville Engine free again turning easily with a Breaker bar & socket.
Its a Rare old engine & wanted one for years.

The 1st thing you want to do is remove all spark plugs and look inside the cylinder bores with a small bright flashlight and check for Heavy Rust.
On my Pontiac 389 I seen mostly clean shiny cylinder walls.
Next you want to remove the oil pan and check for Mechanical damage.
Broken or bent connecting rods.
Broken crankshaft.
Broken main caps or Main cap bolts. Never seen it happen on a Pontiac V8 to date.
Spun main bearings & spun connecting rod bearings.
Sludge or heavy sludge is OK and to be expected on Old Musclecar era engines 1955-1974 into the 1980's.
Engine oils had lots of Zinc additives, often Pariffian based motor oils used.
They survived the 1974 Oil Embargo.
Recessions of 1970's & 1980's and maintenance was not thought much of like today.
Heard stories of Guys back in the day never ever changing motor oil up to 100,000 miles driven.
Kept adding oil when needed.

So we have to deal with what we find for used engines.
All New Ground Up engine ( $15,000 - $200,000.00 ) is OK if you can afford but it will never be 100 % Vintage Chevrolet, Pontiac V8, Cadillac V8, Buick V8, & Oldsmobile V8.
If you look on other car forums there is still a huge following where guys don't want modern LS engines.
I am one of those guys.
Romance & Legacy not there as old Vintage Iron.

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maniacmechanic
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So my 389 has no Mechanical damage.
No Broken parts on the bottom end.
I removed the Valve covers next and looked at the valve train.
No Bent pushrods.
No Bent valves or broken valvesprings.
I loosened all rocker arm pivot nuts 4- 5 turns each.
Then slid each rocker sideways.
Pulled the pushrods out each & checked to see if any were bent.
All passed & A-OK.
You want to look at the valvestem tips...Its a good indication of Mileage & history of the engine.
The valvestem tips on the 389 are still shiny and fresh & square true surfaces.

On High mileage GM engines the valvestem tips are battered to death, divots & craters present.....Bad....Means the engine was abused beat to death. Fucken Junk most likely the engine.

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maniacmechanic
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While the oil pan was off I flipped the engine upside down on my engine stand and with a flashlight examined the Camshaft lobes & Lifter crown faces.
They are readily visible this manner on Chevrolet & Pontiac V8's & most other engines.
All you want to see is clean shiny pit free Flat lifter faces and Nice Camshaft lobes.
Flat camshaft lobes are BAD & lifters with divots and chunks missing Not good.
Rest of engine is likely Junk then too.

Camshaft & Lifters OK in my 389 engine.

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maniacmechanic
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So next I soaked all the cylinders in PB Blaster Penetrant oil.
It did not do Fucken Shit.

SO I purchased AeroKroil Oil from an Ebay Seller.
Stuff used to local to buy but no longer is.
Let it soak for 1 working day.
Engine broke free but took great force with a Pry bar on the Flywheel ring gear and Flywheel Housing.
Sprayed the piston from the bottom side with Kroil and rest of engine internals.
Flipped the engine upside on my stand and soaked down the valvetrain with Kroil oil.
You want to soak the Valvestems & valveguides with Kroil or your choice of penetrating oil.

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maniacmechanic
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So Next I tried Marvel Mystery Oil.
Went to Grumpys site & looked up his concoction brew mix.
Tried it.
No better than before.
Still the engine is tight hard to turn.

I fired up my air compressor.
Valve train backed off, rockers set loose 4-5 turns each the pivot ball jam nuts.
Took my Snap On Compression Gauge and removed the Schraeder check valve.
Inserted the whip hose into each spark plug hole 1 by one and forced 125 psi air pressure in for 1/2 hour each.

Still no better.
Tight yet.

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maniacmechanic
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I then purchased 2 gallons of Evapo Rust remover.
Put into all cylinders till it ran out with a skinny funnel.
Screwed the spark plugs in.
Let the engine sit for 2 days.
A few had the Evapo Rust Remover drain down and back into the oil pan.
That's good & what you want to happen.
Cylinders that didn't gravity drain back to the pan I sucked out the Evapo Rust Remover with a Siphon tool.
Blew out residue with a Blow Gun compressed air.
Took a look with my flashlight inside through the spark plug holes.
Clean & spotless rust free.

Oiled the cylinders with a Mix Of Dextron 3 ATF & Marvel Mystery oil with my oil squirt can.
Still hard to turn over.

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maniacmechanic
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So I researched on the Net....
Went out & purchased Veterinary IODINE.
Found it at my Local Blaine's Farm & Fleet store.
Bought 1 gallon for $8.99.
Went home & poured about 4 inches into each cylinder of the Iodine.
Its an Old Timers trick dating back to the 1930's to free stuck engines sitting 35 - 100 years.
Waited over night that brings us to this past weekend.
When I removed the spark plugs rusty Froth liquid spilled out.
The Iodine cleaned the Hidden rust down in the piston ring grooves and lifted to the Top of cylinder.
I tipped the engine on my stand each way and let the Iodine spill run out.
Brought the engine upright and removed the oil drain pan plug.
Some Iodine ran out too.
A good sign it made it past the piston rings and back into the pan.

Blew the cylinders out with my Blowgun.
Took a look with a flashlight & really spotless clean now.
Like Brand new inside.
Lubed up the cylinders with Castrol Synthetic 10w30 oil.
The engine turns over easier now but still tight.

THE IODINE DID THE BEST JOB THUS FAR FREEING UP MY 1959 PONTIAC 389 ENGINE.

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maniacmechanic
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So I read some more online.
I removed all rust from the cylinders and piston ring grooves & rings with Evapo Rust Remover & IODINE.
But I have done nothing to remove the Aluminum Oxide from the piston ring grooves & surrounding crevice volume areas there.
Its what is Binding up my engine yet.

Bottom end is A-OK as is the Valve train.

I started reading the US Military Vehicle restoration Forums & found my answer.

If you use an acid the cylinder walls, pistons, & rings will be destroyed.
No 2nd chance with Muratic acid.
Some have used but I will not on my 389 Pontiac.

Only one other chemical to remove decades old Aluminum Oxide.
What seizes near all old engines with aluminum pistons tight as drum sitting.
Will update soon.
Let you know the results and chemical I used.

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maniacmechanic
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